Division of Pediatric Emergency Medicine, Stanford University School of Medicine, Stanford, CA, USA.
Acad Emerg Med. 2009 Nov;16(11):1258-65. doi: 10.1111/j.1553-2712.2009.00511.x.
In the emergency department (ED), a significant amount of radiation exposure is due to computed tomography (CT) scans performed for the diagnosis of appendicitis. Children are at increased risk of developing cancer from low-dose radiation and it is therefore desirable to utilize CT only when appropriate. Ultrasonography (US) eliminates radiation but has sensitivity inferior to that of CT. We describe an interdisciplinary initiative to use a staged US and CT pathway to maximize diagnostic accuracy while minimizing radiation exposure.
This was a retrospective outcomes analysis of patients presenting after hours for suspected appendicitis at an academic children's hospital ED over a 6-year period. The pathway established US as the initial imaging modality. CT was recommended only if US was equivocal. Clinical and pathologic outcomes from ED diagnosis and disposition, histopathology and return visits, were correlated with the US and CT. ED diagnosis and disposition, pathology, and return visits were used to determine outcome.
A total of 680 patients met the study criteria. A total of 407 patients (60%) followed the pathway. Two-hundred of these (49%) were managed definitively without CT. A total of 106 patients (26%) had a positive US for appendicitis; 94 (23%) had a negative US. A total of 207 patients had equivocal US with follow-up CT. A total of 144 patients went to the operating room (OR); 10 patients (7%) had negative appendectomies. One case of appendicitis was missed (<0.5%). The sensitivity, specificity, negative predictive value, and positive predictive values of our staged US-CT pathway were 99%, 91%, 99%, and 85%, respectively. A total of 228 of 680 patients (34%) had an equivocal US with no follow-up CT. Of these patients, 10 (4%) went to the OR with one negative appendectomy. A total of 218 patients (32%) were observed clinically without complications.
Half of the patients who were treated using this pathway were managed with definitive US alone with an acceptable negative appendectomy rate (7%) and a missed appendicitis rate of less than 0.5%. Visualization of a normal appendix (negative US) was sufficient to obviate the need for a CT in the authors' experience. Emergency physicians (EPs) used an equivocal US in conjunction with clinical assessment to care for one-third of study patients without a CT and with no known cases of missed appendicitis. These data suggest that by employing US first on all children needing diagnostic imaging for diagnosis of acute appendicitis, radiation exposure may be substantially decreased without a decrease in safety or efficacy.
在急诊科 (ED)，由于对阑尾炎进行诊断而进行的计算机断层扫描 (CT) 检查导致了大量的辐射暴露。儿童因低剂量辐射而患癌症的风险增加，因此最好仅在适当的情况下使用 CT。超声 (US) 消除了辐射，但敏感性低于 CT。我们描述了一种跨学科的倡议，即使用分阶段的 US 和 CT 途径，以最大限度地提高诊断准确性，同时最大限度地减少辐射暴露。
这是对在学术儿童医院 ED 就诊的疑似阑尾炎患者进行的 6 年回顾性结果分析。该途径将 US 作为初始成像方式。仅在 US 结果不确定时才推荐 CT。ED 诊断和处置、组织病理学和随访的临床和病理学结果与 US 和 CT 相关联。ED 诊断和处置、病理学和随访用于确定结果。
共有 680 名患者符合研究标准。共有 407 名患者（60%）遵循了该途径。其中 200 名（49%）无需 CT 即可明确诊断。共有 106 名患者（26%）US 对阑尾炎呈阳性；94 名（23%）US 呈阴性。共有 207 名患者的 US 结果不确定，随后进行了 CT 检查。共有 144 名患者进入手术室（OR）；10 名患者（7%）阑尾切除术阴性。漏诊阑尾炎的病例少于 1 例（<0.5%）。我们的分阶段 US-CT 途径的灵敏度、特异性、阴性预测值和阳性预测值分别为 99%、91%、99%和 85%。共有 680 名患者中的 228 名（34%）US 结果不确定，没有进行后续 CT 检查。其中 10 名患者（4%）因阑尾切除术阴性而进入 OR。共有 218 名患者（32%）经临床观察无并发症。
在使用该途径治疗的患者中，有一半患者通过明确的 US 即可明确诊断，其阑尾切除术阴性率（7%）和漏诊率（<0.5%）可接受。根据作者的经验，阑尾正常（US 阴性）的可视化足以避免 CT 的需要。急诊医师 (EP) 使用不确定的 US 结合临床评估来治疗三分之一的研究患者，而无需进行 CT 检查，并且没有已知的漏诊阑尾炎病例。这些数据表明，通过对所有需要诊断成像以诊断急性阑尾炎的儿童首先进行 US 检查，可以在不降低安全性或疗效的情况下，大大减少辐射暴露。
